Head Meta Tag Description Plugin Question

I have a Wordpress blog and I've found that this plugin can really help to increase your SE rankings. Now I installed the plugin 3 weeks ago and still no change. The search engines see for all my posts the same description, that is bad. Now I've found this post on a blog but I've got the same results when with his advices when I install the plugin and when I don't have it installed.

What can be wrong ?! Any suggestions ?

Thanks

Later Edit : I've noticed that I have two meta descriptions.

<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<meta name="generator" content="WordPress 2.1.1" />
<meta name="template" content="K2 Beta 1.01" />
<meta name="description" content="" />

And one

<link rel="EditURI" type="application/rsd+xml" title="RSD" href="http://mywebsite.com/xmlrpc.php?rsd" />
<meta name="description" content="bla bla bla bla - The good meta description." />
<script type="text/javascript">//<![CDATA[
var live_referrer = document.referrer;
live_referrer = live_referrer.replace(/&/g, '*am*');
live_referrer = live_referrer.replace(/=/g, '*eq*');
live_referrer = live_referrer.replace(/\+/g, '*pl*');
var live_image = new Image();

What do I have to do ?

 

install this plugin: http://guff.szub.net/2005/09/01/head-meta-description/

 

This is the plugin I'm having problems with.

 

Hmmm works for me. What version of Wordpress ?

 

@necromanc

Try the all-in-one-seo-pack from uberdose instead, it doesn't require you to edit the template as long as there is a wp_head in it (most do)

You can find is at wp.uberdose.com/2007/03/24/all-in-one-seo-pack